The Effect of Thermo Reactive Diffusion (TRD) Processing Time with Ferrochromium Powder on Carbide Layer Characteristics on SUJ 2 Tool Steel Substrate (original) (raw)
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IOP Conference Series: Materials Science and Engineering, 2019
Thermal Reactive Deposition (TRD) using pack cementation method with vanadium as carbide former has been examined to form the carbide layer on SUJ2 tool steel. In this study, effect of addition recycled FeV powder to new FeV powder to the product quality. Calculation analysis resulted 4 variations of FeV powder ratio to be studied i.e. 100% new FeV powder; 100% residual FeV powder; new powder FeV : residual FeV powder 50%:50%; New FeV powder : residual FeV powder 25%:75%. Electron microscope (SEM) and optical microscope (OM) analysis showed that the carbide layer formed in each sample had the same relative layer thickness of about 18μ. X-ray diffraction (XRD) characterized showing that there were a vanadium carbide compound in the formed layer. Hardness test and wear test resulted a relatively similar hardness value of about 1800 HV and 3×10−5 mm3/m. It can be concluded that the use of residual FeV powder to the new FeV powder can be applied because the test results with various rat...
2018
This paper presents developments contributing to the improvement of thermo-reactive deposition (TRD) process in producing hard carbide layers, on automotive components application. The problem in using FeV powder as a coating material that has been applied in the industries is it is high cost. In this study, FeCr powder coating material was mixed into FeV powder with a ratio of 35:65 weight percent. The SUJ2 steel pins components are processed at 980° C, with varying TRD time was 4,6,8 and 10 hours. Scanning Electron microscope (SEM), Electron Probe Micro Analyzer (EPMA) and X-ray diffraction (XRD) were applied to analyze the coating layers. The thickness of the carbide layer formed will increase with the longer processing time, which thickness at 4-10 hours is increase from 22.7 to 29.7 micron. The gained thickness tends to be homogeneous. Increasing the TRD process holding time results in a higher hardness of the carbide layerwith hardness at 4, 6, 8 and 10 hours is 2049, 2184, 21...
IOP Conference Series: Materials Science and Engineering
In this study the effect of temperature variation of the thermo-reactive deposition (TRD) process on carbide layer formation on SUJ2 steel substrates by pack cementation using Ferrochromium powder as carbide former was studied. This process was carried out on SUJ2 steel substrates at temperatures of 900, 980 and 1060 °C for 6 hours. The effect of temperature on layer thickness, homogenity and hardness was studied. Results show that the higher the temperature the thicker the layer formed on the substrate surfaces. Furthermore the XRD results show that the layer formed by this process is chromium carbide. The average microhardness of the layer for 3 process temperature variations is around 1750 HV while the wear rate is around 7 x 10-4 mm 3 / m.
IOP Conference Series: Materials Science and Engineering, 2018
In this research, the formation of carbide layer coating on SUJ2 steel by pack Thermal Reactive Deposition method was studied. Mixture of 35/65 weight percent of ferrochromium/ ferrovanadium (FeCr/FeV) powder was applied as coating elements. The process was carried out at temperatures of 900, 950, and 1000 °C for 6 hours for each temperature. The effects of temperature on layer thickness, microstructures, homogeneity, hardness, and wear resistance were analyzed. The result showed that the higher the temperature, the thicker the layer formed on substrate surface. The higher percentage of vanadium in the coating layer compared to chromium found by EDS Linescan results indicate that vanadium has higher affinity to carbon than chromium. This result also means the possibility of vanadium carbide formation will be higher than chromium carbides, due to the lower Gibbs energy for vanadium carbide formation. XRD results showed that the layer formed in this process consists of vanadium carbide (V8C7 and V6C5), chromium carbide (Cr23C6 and Cr7C3), and complex carbides. The average micro hardness and wear rate of all coatings with three different temperature variations were 2100 HV, and 3 x 10-4 mm 3 /m respectively. This hardness was close to FeV hardness as single carbide former at approximately 2400 HV.
A study on kinetics of CrxC-coated high-chromium steel by thermo-reactive diffusion technique
Vacuum, 2005
There are a lot of technologically interesting characteristics of chromium carbide coating deposited by pack method which is the production of hard, wear-resistant, oxidation-and corrosion-resistant coating layer on the steel substrates. In the present study, kinetic study of chromium carbide coating of AISI D2 steel coated by pack method at the temperature of 1223, 1273 and 1323 K for 1-4 h was realized. The presence of phases Cr 7 C 3 and Cr 3 C 2 formed on the surface of steel substrates were confirmed by X-ray diffraction analysis. Cross-sectional observation of optical and SEM back-scattered electron images (SEM-BEI) showed that chromium carbide layer formed on the steel substrates were smooth and compact. The hardness of chromium carbide layer is 1850735 HV 0.025. The kinetics of chromium carbide coating by pack method showed that a parabolic relationship between carbide layer thickness and treatment time, and activation energy for the process is 278 kJ/mol. Moreover, an attempt was made to investigate the possibility of predicting the contour diagram of chromium carbide layer variation and to establish some empirical relationships between process parameters and chromium carbide layer thickness.
Nb–Cr complex carbide coatings on AISI D2 steel produced by the TRD process
Journal of the Brazilian Society of Mechanical Sciences and Engineering, 2014
Nb-Cr complex carbide coatings were produced onto AISI D2 steel by the thermo-reactive diffusion (TRD) process to improve the surface hardness and corrosion resistance of this tool steel. The carbide coating treatment was performed using molten borax added with ferroniobium, ferrochrome and aluminum at temperatures of 1223, 1293 and 1363 K during 2, 3, 4 and 5 h. The coating layers were characterized by optical and Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS) and X-ray fluorescence spectrometry (XRF). The coating growth rates were evaluated, and a model of the layer thickness as a function of the treatment time and temperature was established. The hardness of the coating was measured by nanoindentation, and its resistance to corrosion was evaluated with electrochemical tests of potentiodynamic polarization. The produced carbide layers presented a homogeneous thickness as well as an improved hardness and corrosion resistance as compared to the uncoated steel.
Vanadium carbide coatings on die steel deposited by the thermo-reactive diffusion technique
Journal of Physics and Chemistry of Solids, 2008
Thermal reactive diffusion coating of vanadium carbide on DIN 1.2367 die steel substrate was performed in a powder mixture consisting of ferro-vanadium, ammonium chloride, alumina and naphthalene at 950, 1050 and 1150 1C for 1-5 h. The carbide layers were characterized by means of microstructure, microhardness, X-ray diffraction and chemical analysis. Depending on the coating process time and temperature, the thickness of the vanadium carbide layer formed on the substrate ranged from 2.3 to 23.2 mm. The hardness of vanadium carbide layers was about 2487 HV. Dry wear tests for uncoated and coated DIN 1.2367 die steel were carried out on pin-on-disk configuration and at a sliding speed of 0.13 m/s. The results showed superior wear properties of the coated samples. The kinetics of vanadium carbide coating by the pack method was also studied and the activation energy for the thermo-reactive diffusion process was estimated to be 173.2 kJ/mol.
Surface and Coatings Technology, 2016
Different Thermo-Reactive Diffusion and Deposition (TRD) treatments have been analysed in the present work. The processes were carried out on UNI 42CrMoS4 (AISI 4140) steel both in the nitrided and bare state at temperatures of 825, 900 and 1000°C, the samples being quenched in water afterwards. Hard, compact and adherent vanadium and chromium carbide and vanadium nitride coatings, mainly consisting of Cr7C3 , V6C5 and VN ,were obtained using different processing conditions. Biphasic layers composed by two different carbides were also obtained. The average micro-hardness of the coatings ranged from 1717±170 to 2451±236 HV0.02 whereas Ra values between 0.2 and 1.2 µm were measured. The kinetics of the coatings growth was also studied on the basis of SEM observations. It was demonstrated that the layer thickness is related to the time by a parabolic law and to the temperature by an Arrhenius-like behaviour.
Effect of the Carburizing Layer on the Morphology of Chromium Carbides
Journal of Siberian Federal University. Engineering & Technologies, 2020
Low carbon steel substrates were face-hardened by cementing, after which thin layers of chromium were deposited electrolytically on these substrates. After deposition, the samples were exposed to isothermal annealing at a temperature of 950°C. The characterization of the thin layers was carried out by means of optical microscopy and interferometry using the Vickers microhardness test. The obtained results allowed establishing the phase shift kinetics (under the effect of the cementing layer) in thin layers of chromium, which are transformed into chromium carbide when passing through metastable transition phases. These transformations were due to diffusion of the carbon atoms coming from the layer of cementing, germination and growth in solid phase. This fact has been examined taking into account the annealing temperature, the lattice parameter evolution and the deposited chromium layer morphology. As to mechanical properties, it was established that the micro-hardness depends on the...